Control mechanism



` oct.' 11,1938. QMENS 1f y2,132,919

l CONTROL 4MEGHANISM iled' Jue' 4, 1934 e ,lam @NI Il Ilwll L Patented Oct. l1, 1938v UNITED STATE-SL 2,132,919 f v coN'rnor. vMscmmrsuu v'PAT"ENT osi-lcs i Charles .L rensyChicago, Ill.` Applicticnwnlne 4 1934, SeriallN. 728,853- v i y 1c claims.

This. invention relates to. lcontrol mechanism for moving a controlled or actuated' element rapidly through a relatively wide rangeof movement but having provisions for moving the controlled element accurately and slowly to. aiford a'i'lne or so-called micrometer adjustment at Vany' point throughout said range of movement. The invention is particularly usefull for controlling de.-

vices such as carburetors, for example, on air- 1 craft, or for controlling the tuning or vo1ume\ adjustments of radios. But it is to be understood that the vinvention hasv a general application to any type of control wherein the speciiiedtypes of adjustment are desirable. f

.15 `It is an object of kthe invention to provide ya I. control mechanism by which a controlled or actuated'element may be moved rapidly throughout a wide rangeof movement vbut by which the controlled element may bemoved slowly and movement.

vide a new and improved control mechanism particularly adapted to adjustment of carburetor 25 controls, radioV controls, and the like, but also general utility,'which may be readily and cheaply constructed and which is durable and wholly A efficient in operation. f

ra. control mechanism in Whichthe control han'- dle may oe moved in 'one manner to move the controlled or` actuated element vrapidlythrough a -given range of movement and in which the control handle may be moved in another manner to move the controlled element slowly and ac' curately at any point withinsaid range of movement to effect micrometer adjustments.'

It is a further object ofjthe invention to provide a control mechanism in which a control knob may be displaced longitudinally'to move a controlled element rapidly through/a given range of movement and in which-the control. knob may be rotated to impart a relatively line adjustment to said controlled element at any point throughout said range of movement.'v

It is a still further object to provide in such a control mechanism, means whereby the resistance imparted 'to Athe longitudinal movementof the controlhandle is invariable during operation,

Fig. 1 is an assembly view of onel 'form'of control mechanism embodying the invention. Fig..2 is an enlarged sectional view of a part 6o of the c ontrolmechanism shown in Fig. '1.

accurately at any point within said range1 of It is another object of the invention to provide Other objects and advantagesofthe invention l Fig, 3 is a'sectional view tak'enalong the line 3-3 of Fig. 2 showingthe ball retaining and actuating means. t

Fig. 4 is a sectional detail taken along the line 4 4 of*` Fig. 5 showing a modied gear type retaining and actuating means.

-Fig. 5 is a sectional view of the device shown in Fig.' 4 taken alongthe line 5--5 of Flg. v4.

Fig. 6 is a sectional view taken along the line 'J+S of Figj? showing a'retaining and actuating 1 means similar to .that shown in Figs. 4 and 5 but employing a modified type of mounting, and

Fig. 7 'is aside elevation of they device shown in Fig. 6.

Throughout the drawing like reference nu merals refer to like parts. i

The'invention consists generally in thel provision of a control device embodying provisions for moving a controlled or actuated element rapidly and vreadily through a relatively vwide range'oi.'

movementbut incorporating provisions vfor accurately 'adjusting said controlled element within very fine limits anywhere within said range of movement. In the forms of my inventionwhich Ifhave shown in the drawing for purposes of illustration I provide a control knobwhich may' be moved `bodily to move the controlled element correspondingly rapidly and readily through a relatively wide range of movement, but which may be rotated in any position tol afford ilne adjustment of the controlled element in such position.

Referring now tothe drawing, and particularly to that embodiment 'used for 'illustration whichl 'I have shown in Figs..1, 2 and 3, vnumeral III denotes a suitable'control knob which is adapted y to be grasped by the hand of an operator and displaced bodily from its full line position .to itsl dotted line position, as shown in Fig. l, or rotated about its central axis'. Threaded within the control knob I0 fis a cylindrical collar' I2 which' carries threads upon its inner as well as its outer surface and. has threaded' thereina long sleeve member Il. The collar I2 is'used merely as a Aconvenient means for lmounting the sleeve Il rigidly within the control. knob I0 and during normal operation of the device the parts Il, I2;

and I4 are relatively immovable. l .The sleeve I lis journalled'withina sleeve I6, A the surface I5 of the sleeve Il furnishing a good bearing surface. 4The sleeve v'I6' is threaded at I1 at its end nearest the control knob, as shown in Fig. 2, and'carried by the threads Il are two `cooperating nuts I8 and 20. These two nuts may be rotated in opposite directions being thereby moved together tov clampbetween them' the control panel 22 upon which the control device is mounted and by which it is supported. A suitablelock'washer 24 is arranged between the .controlpanel 22 and-.the lnut 20 to insure thatV the parts will not come loose byv vibration or the like. The nuts I 8 and 20 and the lock wash-- er 24 constitute a convenient means for securing the sleeve I6 rigidly to the control panel 22. Other equivalent mounting means could be provided.

Cut along the surface of the sleeve member I4 to the left of the bearing portion I5, as shown in Fig. 2, is a helically arranged screw thread 10 26. The cross-section of the threadis such that it just fits theexterior surface of a ball 28, which engages with the screw thread 626 through` a suitable circular vope 'ng 30 cut inii the outer sleeve member I6. The all 28-is yieldingly urged intoengagement with the screw thread by means of aspring 32 which encircles the sleeveY I6. In assembling these parts the spring 32, the convolutions of which tend to press resiliently against each other in .non-separated relation, is slipped over the sleeve I6 until the center of the spring lies over the holein the sleeve. jlhe center convolutions of the spring are then forced apart and theball 28 dropped into the hole 36 into position. Upon release, the convolutions of 25 the spring tend to assume their vnormal contacting position, thus resiliently urging the ball into engagement with the screw thread 26. It is obvious that the force with which the ball is urged into engagement with the screwthread may be 3ok adjusted by varying the strength of the spring utilized. j A Within the sleeve I4/at the end adjacentand within the control knob is a cylindrical member 34, /and the sleeve I4 is rotatable upon member` 34. The member 34 'has an enlarged portion 35 at its end which'cooperates with a'similarly enlarged portion on the sleeve I4 which prevents the member 34 from moving longitudinally to the right with respect'to the sleeve, as shown in 40 Fig. 2. The end of the enlarged portion 35 abuts the body of the'control knob, thereby holding.

the. member 34 from longitudinal displacement .to the left with respect to sleeve I4. Rigidly secured within the` hollow central portion of `member 34 is a flexible wire or cable 36 of suitv-able construction.'` Any convenient means may be used for securing the cabley Within the memrber 34 and one satisfactory means, as shown in Fig. 2, consists in bending the end of -it into a hole 38 cut within the member 34. Solder is then poured into the hole` 38 and into the central hollow portion of the member 34, forming Y a seal and a securing means forrigidly securf ing thel cable to the member. Encircling the y wire or cable 36 is a flexible,` helically coiled wire 46. v'The parts 36 and 40 constitute a flexible connecting means capable of transmitting longitudinal force. .The wire coil 40 abuts atv its' v .winding a wire of suitable cross-sectioninto a' helical coil. The sheath 42 may be secured with- .inthe sleeve I6 by projectionsv 44 struck inwardly from the sleeve, andthe sheath-42 may be covered by. .fabric tape or the like, 46. Parts 46, 42, 40 and '36`lmay be extendedjzo any convenient length and constitute a suitable- Aiiexible connection between the control handle on the control panel and the actuated or contrclledelement.`

. Rigidly secured upon the sheath 42 at its end ymerely by rotating the'knob. the knob inner sleeve member I4 rigidly secured 45 near the actuated element is a sleeve 48 which carries rigidly within it a second sleeve 50. Slidable within sleeve 5I) is a'cylindrical member 52 having a central hollowv portion within which. the wire 36 is rigidly secured'by a connection 5 similar'tothe connection between the other end of wire 36 and member 34.` Nuts 54 threaded upon vmember'52 secure -the controlled or actuated element 56 rigidly thereon. The wire coil 40 abuts the member 52 at its right end, as shown l0 in Fig. 1, similarly to the manner in f which the other end of the coil abuts member 34.

The vwire coil 40, the sheath 42 and fabric covering 46, together with the sleeves 48 and k5I) and member 52, constitute merely a conven- 15 is as follows: The control knob I0 may be grasped by the operator and moved bodily with respect to the control panel 22 from its full line position, as shown in Fig. 1 to its dotted line posi- 25 tion, or it may be displacedonly partly through this. range of movement as desired. Due to the connection formed by the wire 36, the controlled member 56 partakes of any displacement imparted tothe control knob. During such dis- 30 placement of the control knob the sleeve I4 to which it is rigidly secured is' correspondingly displaced longitudinally with respect to sleeve I6 xed to the control panel, and during this action the ball 28 yields and snaps from thread .35 to thread along the-threaded portion 26, being held resiliently in engagement with the threads i by the spring 32. `'I'here is no rotation of any of the parts during this operation.

At any point throughout the range of move- 40 ment of the control knob a very fine and accuratekor so-called micrometer adjustment may be im'- parted to the controlled element or member 56 Upon rotation of to the knob rotates'with respect to outer sleeve member I6 rigidly carried by the control panel 22. By reason ofthe engagement of ball 28 with screw thread 26, such relative rotation between' sleeves I6 and I4 produces a relative longitudinal .50' movement between these parts by `screw thread action and,-inasmuch as sleeve I6 is fixed longitudinally with res'pect to the control panel, longitudinal movement is .imparted to sleeve I4, to

" the control knob I6, and by vvirtue of wire 36, to 55 the controlled member 56. The pitch of the thread" 26 determines the amount of llongitudinal displacement which will be imparted to sleeve I4 upon any given rotational movement of the control knob.v It will thus be seen that a means is 6o provided for imparting accurate and relatively small `adjustments to controlled member 56 by relatively large and easily controlled rotation of knob I0. When the controlknob is' rotated, although sleeve I4 rotates, the parts 34, 40, 36, 52 65 and 54 do not rotate due to the fact that members 34 and I4 are relatively rotatable although' not relatively displaceable longitudinally.

By suitab1y-determining the pitch of th'e thread 26 such adjustments of element 56 may be made 70 l .as accurate and small'as desired for any 'normal rotational movement imparted to the control knob I 6; Aspring 3 2 is select-ed which is not strong enough to seriously interfere with the longitudinal .displacementff'movement of the` control knob. 75

c 2,189,919 yThe spring will be strong enough however, to

hold the ball within a thread upon relative rotation of sleeves, I4 and I6, to produce longitudinal movement of sleeve .14. If the control device is appliedlto acontrolled member 56 which requires considerable force to move it, the action of the spring may be aided during rotation yoi' the control knob 'by a slight longitudinal thrust of the operators hand upon the control knobfduring rotation in the direction in'which thel control' fkr'iojb is to be moved by the action of the ball on respect to the x'ed sleeve I6', 'the gear wheel I2 the threads. y r f r 4.

In Figs. 4j and 5 there is disclosed a modified arrangement for imparting longitudinal movement to sleeve I4 uponrotation of the control knob, a'frictionallyl mounted gear vbeing substituted for ban 2a.' In'thisembodiment the Shreve member/ I6 similar to sleeve i6 in Figs. 1,12 and 3, carries a clamp comprising a circular body portion'51 securely embracing the sleeve I6' which has upstanding from itfextensions 58 located lon- 1 gitudinally of the sleeve approximately in the same position asthe Ahole 3.0 in the embodiment of Figs. 1, 2 and 3. Carried` by the extensions 58 is a boltill upon which is rotatably mountedv a gear wheel 62. Cut inthe sleeve i4 is a helical thread 64 similar to the thread 26 in sleeve I4 of Figs. 1, 2` and 3, except that :the shape of the' thread is such that it is adapted to 'iit with threads cut upon the gear wheel 62. The thread 6l and gear 62 form essentially a worm gear and worml wheel arrangement. Gear `62 engages thread 64 through an opening cut in sleeveV i6'. Nuts 86 are providedupon bolt 60, and'by their adjust-` ment substantially any desired frictional drag may 'be placed u'pon gear wheel 62 bydrawing the extensions 58 against the sides of the gear wheel.

The operation of the device of Figs. 4 and 5 is substantially the same asv that disclosed in Figs. 1, 2 and 3, that is, Qn imparting a bodily longitudinal movement to the control member I0,

-the sleeve Il is displaced longitudinally vwith frictonally rotating upon its axis during this rn rigs. s' and 7 there is shown an embodiymentmuch. like thatof Figs. 4 and 5 and employingasimilar i'rictionally mounted gear.

However, a slightlydlil'erentlmeans for adjustf. z

ing f the frictional drag upon the gear wheel is provided., In this embodiment the clamp $1' secured to the sleeve i6' has an upstanding single extension 61 and a blfurcated extension 68 form- 'ing 'two upstanding parts separated slightly,

ask shown in Fig. 7. The bolt 1.6, upon which the' gearwheel I2. is in this instance iixedly mounted, is journalled, within the extension/61 and between the extensions 69) A second bolt 12 passes through the extensions 68 and upon the end of f this bolt are nuts Il by which the extensions Il may be brought together to clamp against the bolt '10 and thereby adjustxthe frictional resistance to 'rotation of the ygear wheel 62'.- The op-` eration of this'embodiment of the invention except for the difference in the means for adjustling `the irictional resistancevof gear wheel 62' is the same vas is thev operation of theembodiment `shown in Figs. 4 and `5.

V'Ihe invention thus provides means for reariilyv and quickly moving a controlled element throughout a wide range of`movement but also `provides means forpvimpartingl accurate land tine adjustments 'to the controlled/.element atany point within such range of movement. The invention has particular applicability,y for example,

.longitudinally the engine could be operated,

throughout its entirefpower range. readily and quickly.' However, at'any given position of the control the member. 56 could be accurately and voperation to accommodate movement ofthe sleeve i4. The frictional drag imparted to' gear wheel 62 by adjustment of nut 66 isnot sumcient to prevent this relativel displacement of thel sleeves; However, upon rotation of the control `knob and sleeve I4' Withrespect to `sleeve I6', the frlctional` produce the precise and exact 'engine speed wanted.-v This is VVa material advantage. With. `ordinary control mechanisms it is impossible to secure a precise yand accurate engine speedv and @still have iiexibility of control which allows'rapid drag upon gear wheel viii holds it stationary so f that sleeve I v4'Acis moved longitudinally vby, screw thread action I any tendency upon the partI ofthe gear wheel 62 to move upon rotation of the control `knob I0 may be avoided by theV operator applying longitudinal force `tov the -control knob in the direction in which it is to move.

'An advantage is provided by the construction shown in Figs. 4 and 5 over that of Figs. 1,- 2 and 3 whichw'may. be very material in some instances. This'advantage resides inV longitudinal displacement adjustment of the con- ;tolknob the gear wheel. 62 imparts'a'uniform asfin the embodimentv of Figs. 1" 2 and 3. As previously described, if considerable force is required to move the controlled member the fact that upon the resistance to the movementof vthe control knob -fandftherefore'does not interfere with accurate adjustment. In the embodiment otFigs. 1, 2-and 3 the ball 28 jumps fromthread to thread proplacement of the c'ontrol knob, andfu'rther dtermines minimum increments of ,movementA control knob must be dis-` 1 i 'i without rotation.

through which the placed.

ducing an uneven. resistance to longitudinal dls- Y control adjustment throughoutv the' entire engine y power-range.' The invention likewisehas par'-r ticularapplicability to the control devices of radios.whereifn, for example, it is necessary .and desirable to tunel or. adjust vvolume rapidly throughout a widerange and'yet have provision for making kaccurate or so-called micrometer ad- V,iustments at any point within that range. The

invention-however relates to control mechanisms broadly and is byno means limited in use-to aircraft, engines,A or radios. l It is of general utility.

It is obvious that various changes may be made in the specic' embodiments of my. invention which I have used for illustrative purposes and.

Itherei'ore do not wish to be limited to the pre# the following' claims. .I claim:` Y I 1. In a control mechanismamovable control cise construction shown, but onlyas indicatedinv y device, and means vfior controlling the movements of the control device, saidmeans comprising a member adapted for rotational movement and' for longitudinal displacement, said member having a screw thread thereon, a rotatable `reactance 'nely adjusted Ahy'rotation of control knob I l to device in engagemenhwith said screw thread,

said reaotance device being rotatable by the screw thread Aas saidv member is longitudinally and means for im-k parting uniform resistance to rotation yof the reactance ,device whereby toY impart uniform resistance to such longitudinal displacement Vof said member, said resistance means also serving to hold the reactance device against rotation during rotation of the screw thread member whereby to impart longitudinal displacement to the member during rotation thereof. Y

having a screw thread thereon, a rotatable' reactance device in engagement with said screw thread, said reactance device being rotatable by the screw thread as said member is longitudinally displaced without` rotation, and means for imparting frictional resistance to rotation of the reactance device whereby to impart resistance to such longitudinal displacement of said member, saldi frictional resistance means also serving to hold the reactance device against rotation during rotation device in engagement with sid screw thread, f

` v longitudinal displacement of said member, said of the screw thread member whereby to impart longitudinal displacement to the member during rotation thereof. i

3. In a control mechanism, a movable control' device, and means for controlling the movements of the control device, said means comprising a for longitudinal displacement, said member having a screw thread thereon, a. rotatable reactance -ber whereby to imp-art'longitudinal displacement to the member during rotation thereof, and means for adjusting said-.frictional resistance means.

4. In a control mechanism, a movableccntrol device, and means for controlling the movements of the control device, saidmeans comprising a member adapted 4for rotational movement and,

for longitudinal displacement, said member having a series of control ridges thereon, a rotatable reactance device having a series. of cooperating control grooves in engagement with vsaid ridges;

said reactance device beingl rotatable bythe ridgesk a-s said member is longitudinally displaced withcnt rotation, and-means for imparting uniform resistanceto rotation of said reactance device wherebyto impart uniform resistance to such resistancemeans also serving to hold'the' reactance device against rotation during rotation of said member whereby said member is constrained during rotation thereof for only such longitudinal displacement as imparted thereto by-the controlwridges. o i

5. In a. control mechanism, a movablecontrol device, and means for controlling the movements of the controldevice, said means comprising a 4member adapted for rotational movement and for longitudinal displimenient, said 'member having a series of control ridges thereon, a gear wheel in engagement with said ridges, said gear wheel 4 6. In a control mechanism,4 a movable controlV handle, and means for controlling the movements I Y of the' control handle, said means comprising a' member capable of rotationand longitudinal displacement only and adapted for movement by the control handle, a friction piece cooperable with saidomember and maintained in engagement' therewith to apply uniform frictional resistance to said member during longitudinal displacement thereof without rotation, said friction piece being yieldable to allow such displacement and being operable by reason of its own engagement with said member to impart longitudinal displacement to the member during rotation of the member.

'7. In a control mechanism, a movable control device, and means for controlling the movements of the control device, said means comprising a member adapted for rotational movement and member adapted for rotational movement and for longitudinal displacemenmsaid member having a screw thread formed thereon, a gear wheel in engagement with said screw thread, and friction means for resisting rotation of said gear wheel.

8. In' a control mechanism, a movable control device,- and means for controlling the movements of the'ccntrol device, said means comprising a member adapted for rotational movement and for longitudinal displacement, said member having a screw-thread formed thereon, a gear wheel in enf,-

gagement with said screwthread, friction means for resistingi rotationl of said gear` wheel, and means fcr adjusting said friction means. ,Y v

9. Control mechanism Vcomprising 'a control Iirnob and an actuated member, connectionsbetween'said Vcontrol knob and actuated member including a screw thread, said screw thread being rotatable and bodily displaceable by said control knob, a sleeve yencircling said screw thread having an opening therein, means carried on said sleeve having upstanding projections, a gear `ing the pressure applied by said clamp.

10. In a control mechanism for aircraft engines, a controi handle, an 'engine power control member, a wire secured at one end to said control handle and at the other end to said control member, a sleeve encircling said wire having a scier.1

.thread cut therein,- a second sleeve encircling said first 'mentioned sleeve having an opening therein, a gear wheel engaging said screw thread through said opening, and means for resisting movement of said gear wheel, said means comprising a friction clamp device, and an adjustment screw for varying the pressure applied by said'clamp.

CHARLES A. ARENs. 

